It is has been proposed to provide active agents, such as caffeine, vitamins and supplements or pharmaceutical products, in a particulate form for oral composition. Some active agents impart a poor or bitter taste when they contact the taste buds of the user.
Attempts have been made to mitigate or reduce the poor or bitter taste ordinarily imparted by a poor or bitter tasting agent when taken in the form of an oral particulate composition. These attempts include encapsulating the poor or bitter tasting agent in a non-poor or bitter tasting encapsulant, such as a lipid or carbohydrate, and/or mixing a flavour-masking agent, taste receptor blocker or taste receptor competitor with the poor or bitter tasting agent.
A known product, marketed as Firestar™, provides an oral dosage form of caffeine, a bitter tasting agent. The product comprises of a particulate composition of encapsulated caffeine particles, carrier particles of caster sugar, and flavouring. The caster sugar and flavouring function to reduce the bitter taste of the caffeine. In particular the flavouring acts to block the taste receptors and/or compete with the bitter flavour of the caffeine. The caster sugar works by reducing the amount of encapsulated caffeine particles which come into contact with taste receptors on the tongue, essentially diluting the effect of the bitter caffeine flavour, and by providing a sweet taste which competes with and/or masks the bitter taste ordinarily imparted by the caffeine particles. The sugar and the flavouring each stimulate saliva production which may lead to more rapid swallowing of the encapsulated caffeine particles, and the caster sugar and/or the flavouring may help to carry the encapsulated caffeine particles out of the mouth to be swallowed. The caster sugar and flavouring thereby reduce the residence time in the mouth of the bitter-tasting caffeine component. The caster sugar dissolves far more rapidly in the mouth than the encapsulated caffeine. These factors separately and collectively promote the sweet taste of the sugar over the bitter taste of the caffeine.
While the encapsulation, the caster sugar and the flavouring may be very effective at blocking or masking the bitter taste of the active caffeine component, the inventor in the present case has recognised that a bitter aftertaste may nonetheless reside in the mouth after the composition, comprising the encapsulated caffeine, caster sugar and flavouring, has substantially been swallowed. This may occur when the encapsulated caffeine particles are resident in the mouth long enough for the caffeine to at least partially dissolve and to contact the taste buds. This may occur when the majority of the caster sugar and flavouring has dissolved and/or been swallowed before all of the caffeine has. Retention of at least some of the encapsulated caffeine particles in the mouth longer than the other ingredients in the mouth may occur if encapsulated caffeine particles become trapped in the mouth, for example in the grooves of the tongue. The result is that a bitter or unpleasant aftertaste may persist after the bulk of the composition has been swallowed.
More generally, oral particulate compositions comprising a poor or bitter tasting active component and a carrier component (such as a sugar and/or a flavouring), in which the carrier component mitigates the effect of the bitter taste in the manner described above, may give rise to a bitter aftertaste when some of the poor or bitter tasting active component is retained in the mouth longer than the carrier component, and/or has a flavour profile which is longer-lasting than that of the carrier component. An aftertaste may also be experienced when not enough of the carrier component is provided so that the active component is not washed from the mouth sufficiently quickly to avoid release of the poor or bitter taste.
At least some of the above problems are addressed by embodiments of the invention.